This invention relates generally to trocars or access ports used in endoscopic or laparoscopic surgeries and more particularly, to flat blade shielded obturators.
A surgical access port or trocar generally has a cannula and a valve housing coupled to one end of the cannula and an obturator inserted into the cannula has a shaft with a sharp blade or tip at one end of the shaft. In operation, the trocar cannula extends across a body wall, e.g., the abdominal wall, providing access into a body cavity, such as the abdominal cavity. The obturator facilitates the placement of the trocar by puncturing and/or penetrating the tissue forming the body wall.
In one example, the obturator is inserted through the cannula and its sharp bladed tip extends beyond one end of the cannula. The sharp bladed tip of the obturator cuts tissue as the trocar and obturator are moved through the body wall. Once the trocar and obturator are operatively positioned, the obturator can be removed from the trocar body leaving the cannula to provide working-channel access into the body cavity.
With the body wall penetrated, the sharp bladed tip can be covered or protected. For example, a spring-loaded tubular safety shield which surrounds the shaft of the obturator may move forward to cover the tip of the obturator once resistance to the movement of the safety shield, e.g., from the body wall, is removed. As such, the cutting stops once the body wall has been penetrated. However, a relatively large force may be required to cause the tip of an obturator to penetrate the body wall. Once the tip penetrates the body wall, resistance to penetration is removed and the tip of the obturator is suddenly free to reach into the body cavity and cause additional cutting. Failure to stop this cutting action can result in complications. Obturators having spring-loaded tubular safety shields may require larger incisions and may require considerable time to move the shield to cover the tip, the shield possessing a relatively large mass.